Buying them is the cheap part. Keeping them flying is the expensive part. And that's not counting fuel.
I think the risk of this thing falling down is quite big.....
Remember the movie... the right stuff... where wives had to go to funeral mostly every week... because of test pilots crashing their X1 planes....
I think perhaps even the X1's will be safe compared to old outdated Mig 21's....... that are not maintained according to proper procedures.....
Here in Norway the F16's will not even take off if the logistics system is down or the logistics system say it's ok to fly... they have control of every little small part, like the tiniest screw in some unimportant part of the plane, they can tell how many flight hours this tiny screw has and when it's due for replacement.... all to keep security up and planes flying
I'm 100% sure US armed forces do the same with all their planes......
don't say this about Mig 21's bought from a website....
Security here is not so good.......